Solo/Duo and Team Ranked Requirements

16 champs is a necessity in the event that you are last pick and for some weird chance that 6 of your champs were banned and then the other 9 players picked champs you own, then that ensures you will always have at least 1 champion that you own that has not been banned or picked. So no, it may be as unlikely as winning the lottery, but it is not arbitrary.

Also, I think they could alter a single feature that would accommodate you. If they placed all new ranked players into a separate queue until they reach an ELO of 1300 or until they play 30 ranked games. Then you'd only get people that have some skills or experience. Someone with 30 ranked games will have far more experience than someone with 300 non-ranked games since the skill level is vastly different.

In my opinion it is necessary to request a minimum of normal games won, as I said before, they can't play ranked queue with 100 wins in normal, because that means they got to level 30 playing custom games vs bot or vs AI.

Consider that a person with less than 200 normal wins, I get to level 30 or just playing custom games vs AI cop, where the difficulty is minimal, the bots do not use the grass to hide and throw skills, bots don't go after a wall and use flash to escape to you, bots don't wait in the grass in front of baron to expect the enemy team to force a teamfight, those things I think you learn in 5v5 team, or in normal, where the vast most people respect the "betagame" adc + Support bot, Ap mid, Top and Jungle Fighter.